An explosion ripped through a sewage plant in a town outside Moscow on Saturday, killing at least one person and injuring 12, the Emergency Situations Ministry said. Authorities did not know what caused the blast in the town of Pavshino, about 5 kilometers west of Moscow, but ministry spokeswoman Natalia Lukash said they had ruled out terrorism. The explosion caused the roof of the three-story structure to cave in, Lukash said. One of the four people working the early morning shift was found injured in the rubble, while the body of a second person was found. Two more were missing, she said. Four people who lived in temporary housing near the sewage plant were hospitalized along with the injured shift worker, while others had more minor injuries. Water supplies to the town were cut, Lukash said.